Submarine mine-layer



Jan. 2, 1934. F. MARTINOLI ET AL SUBMARI NE MINE LAYER Filed March 51, 1932 Patented Jan. 2 1934 UNITED STATES SUBMARINE MINE-LAYER Federico Martinoli, Trieste, and Ermanno Gerolimich, Monfalcone, Italy Application March 31, 1932, Serial No. 602,282,

and in Italy October 23, 1931 2 Claims. (01. 114 17) This invention relates to the type of submarine mine layer, in which mines are accommodated in a series of vertical or substantially vertical storage wells built into the hull of the vessel and open to the sea, so that the laying of the mines is effected by simple dropping of them from the storage wells.

The object of this invention is to provide an improved construction of the above type of submarine minelayer, which will enable a greater number of mines to be carried for a given size of vessel, as compared with known constructions.

In submarines of this type first hereinbefore referred to, it was necessary to fit the mine storage wells at or near the ends of the hull, for the reason that lack of breadth of the central compartments of the hull made it impossible to arrange mine storage wells therein in addition to the other large machines and fittings which have to be housed in these compartments.

As the number of mines to be carried by a submarine mine layer of this type depends principally on the number of mine storage wells as well as on the number of mines which can be accommodated in each well, it followed clearly that for a given size of vessel, the number of mines carried could be increased only by increasing the number and the height of the mine storage wells.

The-present invention has for its object to attain the result above referred to, without any substantial increase of the weight and therefore in displacement hull.

The increased number and height of the mine storage wells has been accomplished by rendering it possible to arrange the wells in way of the central part of the hull, thus increasing the available length and heightfor the fitting of the wells.

For this purpose the usual circular transverse section of the hull has been discarded and one of the known transverse section contour of the pluri-arc type has been adopted along a substantial length of the central part of the hull, and characterized by having a breadth which is larger than its height. In this way the necessary breadth of the central compartments of the hull is obtained to allow the fitting of the mine wells in addition to the other machines and fittings.

A further important advantage of the arrangement of the mine storage wells in way of the centre part of this type of hull is that the wells, owing to their great vertical stiifness and their being built into the hull, form a strength component thereof, adapted to withstand the compression stresses acting in the vertical fore and aft centre plane of this type of hull when submitted to the external hydraulic pressure.

In this way special supporting structures which, in a submarine hull of the type above referred to, are necessary in order to withstand above mentioned compression stresses, can be dispensed with and therefore also the weight of the hull resulting is practically equal to that of a hull with plain circular sections.

Another advantage of the arrangement above referred to lies in the fact that, if desired, the end compartments can be left free of mine wells, thus enabling the arrangement of torpedo tubes at the ends of the vessel and at the same time keeping-a substantial armament of mines.

The accompanying drawing illustrates one embodiment of the invention by way of example:

In the drawing:

Figure l is a vertical fore and aft section through a submarine minelayer in accordance With the invention.

Figure 2 is a horizontal fore and aft section through the vessel taken along the line 2 2 of Figure l, and,

Figures 3, 4, 5 and 6 are vertical transverse sections through the vessel, taken respectively on the section lines 33,4=--4, 55 and 6-6 of Figure 1.

All the figures of the drawing are diagrammatic and like reference characters indicate like parts in thevarious figures.

As will be observed, in this embodiment of the invention, the mine wells are located in the central portion only of the vessels hull, the end compartments of the hull being used for the arrangement of torpedo tubes and torpedoes.

In this embodiment the transverse section contour of the central part of the hull is formed by two symmetrical arcs of circles, intersecting each other in the fore and aft vertical central plane of the hull. V

In the drawing, 1 denotes the shell of the main hull of the vessel, 2 the light structure fitted outside of the main hull, 3 the mine wells, 4 the torpedo tubes, of which, as will be noticed, there are four at the bow and two at the stern of the vessel, 5 the mines and 6 thecompensating tanks for the mines.

The curved chain-line appearing in Figure 2 and marked dis a line passing through the centres of curvature of the transverse sectional contour of the main hull 1. See also Figure 4, from which it will be observed that the said transverse sectional contour of the hull is built up of two similar arcs struck, respectively, from centres located on the lines 01 and intersecting one another, at the top and bottom of the hull, in the vertical centre line thereof, the angles a subtended by the arcs being greater than 180. This crosssectional contour of the hull extends thruout that portion of the vessels hull in which the mine Wells are located, as is indicated by the extent of the aforesaid chain-line d in Figure 2.

The mine wells 3 are of circular horizontal cross-section, and, being of substantial scantlings and built into the main hull of the vessel as integral strength components thereof, and, further, being disposed, as they are, along the centre line of the vessel so that their centres intersect the points of intersection of the hull contour arcs a, they serve as struts or pillars to withstand the compression stresses 0 which are the resultant of the two tangential stresses 1) exerted on either side of the aforesaid point of intersection of the arcs a by the two side portions respectively of the hull.

Each mine well 3 accommodates, as shown, three mines superposed one above the other in the well. These mines are arranged to be released in succession from each well, suitable releasing mechanism being provided as usual for this purpose.

The compensating tanks 6 are provided for the purpose of compensating for loss or gain of gross weight of the loaded submarine as the mines are laid, that is to say, in the event of the mines being of greater or less weight than the water which they displace. They are, therefore, provided with seacocks, pumps and other necessary means for flooding and emptying them as required.

In this connection, it will be observed that the compensating tanks 6 are located in close proximity to the mine Wells. This arrangement is advantageous, as will be appreciated, as by the practice of flooding a tank adjacent a mine well from which a mine or mines have been discharged, difiiculties of preserving trim of the vessel are reduced or eliminated, the compensating water admitted to or ejected from the tank being located approximately at the same point at which the loss or gain of weighthas occurred through the discharge of the mines.

A further feature as to the compensating tanks is that they are directly secured to the plating of the mine wells and thereby serve to strengthen the wells and indirectly, therefore, the main hull of the vessel.

As will be appreciated by those acquainted with the design and construction of submarine minelayers, the improved construction of hull hereinbefore described and illustrated in the accompanying drawing is eminently advantageous in a minelayer, more especially from the point of view of conservation of weight, since a material part of the actual structure of the hull is utilized at the same time for the accommodation of mines.

Further, it will be noted that by employing a cross-sectional hull contour of the form shown in Figure 4, the interior of the hull is rendered considerably more spacious on either side of the series of mine wells, as compared with the amount of room that would be available if a plain circular cross-section were employed for the hull. This increased space in the hull of the vessel permits the installation of propelling motors, storage batteries and other machinery, of larger dimensions and corresponding greater power-capacity, than would otherwise be possible, at least with the same convenience. Also the additional space referred to aiiords' enhanced protection of the mine wells and the mines within them in the event of broadside collision of the vessel, and by disposing the wells in the centre portion of the vessel instead of in end compartments as hitherto, they are further protected from damage in the event of endon collisions. v

Further, a submarine hull contour as shown in Figure 4 is found to have greater stability and sea-worthiness than one with a plain circular contour.

It will be observed that the hull contour illustrated in Figure 4 extends only along the centre portion of the hull, that is to say, the portion along which the series of minelayers extend, and that the two ends of the hull are of plain circular cross-section as shown in Figures 5 and 6. I! desired, however, the cross-section of Figure 4 may be made to extend the full length, or substantially so, of the vessels hull.

What is claimed is:

l. A mine laying submarine boat having its transverse sectional contour in the form of two similar rounded arcs symmetrically disposed on either side of a vertical central plane of the boat, these arcs gradually merging fore and aft into one cross-sectional are near the boat ends and. vertical mine wells fitted in a'vertical plane extending fore and aft from the center of the boat, said mine wells being located along the central portion of the boat and framed together where V the two arcs intersect so as to form strength com ponents of the boat hull whereby the centrally arranged mine well structure combined with the two cross-sectional circular are shaped hull portions act together for withstanding the pressure stresses which exist in the fore and aft central part ofthe hull when the boat is submerged.

2. A mine laying submarine boat as claimed in claim 7, wherein between each two mine wells and in the same plane therewith a mine compensating tank is fitted and directly connected to the wells to contribute to the strength of the same anclto avoid change of trimoi the boat during the laying of the mines.

FEDERICO MARTINOLI. ERMANNO GEROLIMICH. 

